From 86ff7e4d452df6bea362e00bc9c3d7e41ce619c7 Mon Sep 17 00:00:00 2001
From: Alex Yatskov <alex@foosoft.net>
Date: Thu, 2 Apr 2015 23:47:22 +0900
Subject: [PATCH] Changing format

---
 link.go | 42 +++++++++++++++++++++++++++++-------------
 task.go |  2 ++
 2 files changed, 31 insertions(+), 13 deletions(-)

diff --git a/link.go b/link.go
index afa63c6..cf863c1 100644
--- a/link.go
+++ b/link.go
@@ -29,11 +29,6 @@ import (
 	"path"
 )
 
-type link struct {
-	Dst string
-	Src string
-}
-
 func cleanPath(loc string, flags int) error {
 	verbose := flags&optVerbose == optVerbose
 
@@ -74,13 +69,34 @@ func prepInstallPath(loc string, flags int) error {
 	return cleanPath(loc, flags)
 }
 
-func (this link) install(srcDir, dstDir string, flags int) error {
-	if len(this.Dst) == 0 {
-		this.Dst = this.Src
+func (this *link) source() string {
+	if len(*this) > 0 {
+		return (*this)[0]
 	}
 
-	srcPath := path.Join(srcDir, this.Src)
-	dstPath := path.Join(dstDir, this.Dst)
+	return ""
+}
+
+func (this *link) destination() string {
+	if len(*this) > 1 {
+		return (*this)[1]
+	}
+
+	return this.source()
+}
+
+func (this *link) valid() bool {
+	length := len(*this)
+	return length >= 1 && length <= 2
+}
+
+func (this *link) install(srcDir, dstDir string, flags int) error {
+	if !this.valid() {
+		return fmt.Errorf("Link element is invalid")
+	}
+
+	srcPath := path.Join(srcDir, this.source())
+	dstPath := path.Join(dstDir, this.destination())
 
 	if _, err := os.Stat(srcPath); os.IsNotExist(err) {
 		return fmt.Errorf("Source path does not exist in filesystem: '%s'", srcPath)
@@ -98,9 +114,9 @@ func (this link) install(srcDir, dstDir string, flags int) error {
 }
 
 func (this *link) uninstall(dstDir string, flags int) error {
-	if len(this.Dst) == 0 {
-		this.Dst = this.Src
+	if !this.valid() {
+		return fmt.Errorf("Link element is invalid")
 	}
 
-	return cleanPath(path.Join(dstDir, this.Dst), flags)
+	return cleanPath(path.Join(dstDir, this.destination()), flags)
 }
diff --git a/task.go b/task.go
index 770d252..6d5e0a7 100644
--- a/task.go
+++ b/task.go
@@ -24,6 +24,8 @@ package main
 
 import "fmt"
 
+type link []string
+
 type task struct {
 	Deps  []string
 	Links []link